Abstract
The ectoparasitic mite Varroa destructor is considered one of the main threats to the western honey bee (Apis mellifera). Efficient pest management is crucial, and the evaporation of formic acid (FA) is an active principle that could be adopted. However, the usage of FA has an extreme variable efficacy depending on several conditions, ambient temperature among them. Cooler conditions, as they usually occur in Central Europe in late summer and autumn, can negatively affect treatment success. Our study aims to evaluate factors that influence the efficacy of different FA treatments. Over a period of 8 years, we investigated the effect of ambient temperature, hive size and dispenser type on the treatment success with 60% and 85% FA and consolidated those factors in a linear regression model. Treatment with 60% FA shows higher variability, and often lowered efficacy, especially in double brood chamber hives. In contrast, 85% FA treatment achieves higher efficacy and lower variability and shows significantly diminished dependence on ambient temperature.
Highlights
The mite Varroa destructor (Anderson and Trueman) is an almost globally distributed ectoparasite of the western honey bee (Apis mellifera L.)
We investigated the effect of ambient temperature, hive size and type of dispenser on the efficacy of treatments with 60% and 85% formic acid (FA)
Hive size, FA concentration, ambient temperature and type of dispenser remained as predictor variables in the linear regression model, as they all have a significant influence on the treatment efficacy (Fig. 1, F (4335) = 27.61, p < 0.001)
Summary
The mite Varroa destructor (Anderson and Trueman) is an almost globally distributed ectoparasite of the western honey bee (Apis mellifera L.). It originates in Southeast Asia, where it can be found in colonies of the Asian honey bee A. cerana. At the beginning of the twentieth century, by enhancing the efficacy of transport and trade, western honey bee colonies were imported to Asia and coexisted with Asian honey bee species (Oldroyd 1999). Around 1960, it was first discovered that Varroa successfully had switched to western honey bee populations through the sympatric cohabitation of both Apis species (Delfinado 1963). In regions without geographical barriers, the transfer of V. destructor to other colonies was further enhanced through robbing, drifting of drones and worker bee homing errors (Seeley and Smith 2015), and via combining hives, transferring food stores between hives and high bee densities (Fries and Camazine 2001)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
